Deposit social security, Medicare, and withheld income tax for payments on February 10, 11, 12, and 13 if semi-weekly depositor.

Shortfall deposits by semi-weekly depositors for 2018 deposits made January 3 to 31.

Begin withholding income tax from the pay of any employee who claimed exemption from withholding in 2017, but didn't provide a Form W-4 to continue to claim the exemption from income tax withholding in 2018.